Apparatus for cleansing tubular elements



May 1s, 1943 s. A. BRowN ETAL 2,319,531

- APPARATUS FOR CLEANSING TUBULAR ELEMENTS Filed Jan. 6, 1941 M, M2M.,

llouwg Patented May 18, 1943 APPARATUS FOR CLEANSING TUBULAR v ELEMENTS Ethan Allan Brown, Boston, and Norbert Benotti, Weston, Mass.; said Benotti assigner to said Brown Application January 6, 1941, Serial No. 373,364

` 2 Claims.

The present invention relates to cleansing or sterilizing apparatus and particularly to apparatus for cleansing elongated tubular elements such for instance as pipettes. Pipettes, which are elongated tubes of relatively small diameter, usually fabricated of glass, are utilized in substantial numbers in hospitals and laboratories and other places where it is desired to measure accurately small volumes of liquidi, and are usually required to be chemically clean when taken up for use. Cleaning pipettes has heretofore, in the usual case, been effected with the aid of chromic acid, each pipette being immersed in the acid and thereafter rinsed to remove any traces of vacid which had not drained from the pipette upon its removal from the bath.

A primary purpose of the present invention is to provide an apparatus by means of which elongated elements such for instance as pipettes may be thoroughly and effectively cleansed and, if desired, rendered entirely sterile, the operations being not only effectively carried out but ln a practically automatic manner so that but little time need be devoted to the task by the one whose duty it is to obtain the desired result. While the apparatus has been designed particularly for the purpose of chemically cleaning tubular elements suchras pipettes, it will be appreciated by one skilled in the art that the apparatus is eminently suitable for rendering sterile elongated tubular elements of other types and objects of other shapes. y

The complete apparatus contemplated by the A present invention includes three principal elements, the first being a holder into which may be placed pipettes or tubes after they are soiled in use, the holder having capacity to receive a substantial number ofr the Vtubular elements, the other two pieces of apparatus comprising containers within which the holder may be successively placed, one of the containers being a simple tubular receptacle to receive and vhold a body or bath of chromic acid, the second container, or the third and final piece of apparatus,

being generally similar to the second but having means for intermittently flooding the same with fluid and emptying jthe fluid thus introduced, so that when the holder is placed Within this second container the tubes or pipettes which it contains are automatically subjected to successive washings with a suitable washing fluid, generally water. When the holder containing soiledppettes or the like is placed in the acid container, the acid will contactwith all areas of each and will dissolve extraneous matter and render such surface absolutely clean and sterile, the holder with its contents being allowed to remain in the bath of acid for a length of time quite sufcient to ensure destruction of any organic or inorganic material which may be located upon the pipette surfaces or upon the surfaces of the holder itself.

Where the apparatus is employed in a laboratory, it is customary to allow the pipettes and the holder in which they are supported to remain in the acid bath overnight. Thereafter the holder is removed from the first container and isplaced in the second container which, as has previously been explained, is provided with means for automatically flooding it with rinsing liquid and thereafter emptying this body of liquid so that the pipettes or tubes whichhave previously been immersed in acid are subjected to repeated immersions in clean rinsing liquid in an entirely automatic manner. No attendant is required to concern himself with the operation of the apparatus during either the acid treatment step or the rinsing step and the entire cleansing operation is not only carried out in the most effective and eicient manner but with only the slightest amount of attention.

The invention may be embodied in apparatus the various elements of which vary in design and arrangement and one form of the invention which has been heretofore employed with eminent success in the cleansing of pipettes is illustrated by way of example in the accompanying drawing, in which:

Figure 1 shows the holder partially in section and partially in elevation, together with the first container, or the acid bath container, which is shown in axial section;

Figure 2 is a generally similar view but showing the holder positioned in the rinsing container;

Figure 3 is a section on line 3-3 of Figure l; and

Figure 4 is a section on line 4-4 of Figure 2.

The holder is generaly indicated by the numeral I0 in .the drawing, the acid container by the numeral Il, and the rinsing liquid container by the numeral I2. The holder Il! is in the form of a tube the diameter of `which is relatively small as compared with its length, which is open at it stop, and the bottom I0 of which is perforated for the passage of fluid, the tube being preferably a hollow cylinder of glass and its bottom IB being an upwardly bulging and preferably conical member provided with a plurality ofperforations Il)2 by means of which liquid can pass into the interior of the holder or escape therefrom. At its apex or highest point the bottom Ill is provided with an opening and a tubular extension Iii3 the annular end surface of which is disposed in a plane inclined to the horizontal, It will also be observed that the conical bottom is projected outwardly beyond the outer surface of the cylindrical portion ID of the tube and the annular edge or periphery of the corneal bottom is adapted to engage any flat supporting. surface, and to function as a standard or supporting base for the holder, which may be placed on a table, floor, or upon any at surface to support the holder in an upright position to receive soiled tubes or pipettes.

Several pipettes are indicated by the numerals I3, I3 and it will be perceived that the end surfaces of each pipette are normal to its. axis so that the lower end of the pipette will have point contact only with the upper surface of the conical'bottorn lll" of the holder, or with the inclined upper surface of the tubular extension. ID3. .This makes certain thatV the opening in the bottom of each pipette will notv be blocked or obstructed inv such manner that the flow of liquid into or i,

out of the interior of the pipette will be hindered. The holder, as will be observed, is somewhat longer than the container Il', also longer than the container i2 so that, when placed in either of these containers, its. top portion will protrude. g.

This'is toprovide the attendant. with a convenient grasping portion, the upper end of'V the holder in reality comprising. a handle by means of which the-holder may be lifted, transported, and placed where desired. The diameterof` the conical member lil" is, at its base, only slightly less than. the diameter of the container II.. This'ensures that the holder must be moved downwardly inthe container l i relatively slowly when it is first in troduced, permitting the contained acid to flow into. the interior of the holdery through. the apertures in the bottom, eliminating` the possibility of: displacing the acid bath so rapidly astio cause it to overflow from the container I'i, and safeguarding thesel two elements. ofi the apparatus against possibleY breakage due to rapid impact, both being of glass andI therefore rather easily broken. This slow descent also allows the oisans .ing Fluid to rise slowly in the pipettes, sweeping them upwards and so washing out the substances which soiled them..

When the holder is placed in the container i2, it occupies the same relative. position in that container as it does in the container i l, as readily perceived from: nspect-ion of Figure 2. Container i12' is provided withmeans for introducing a rinsing liquid, for instance-water; into the same at the bottom and with means for automatically emptying the container after: each flooding sov that pipettes within the holder are repeatedly bathed wtih successive applications of clean rinsing liquid until all traces of the acid previously applied for cleaning purposes have been removed.

Thus, container l2 is provided at av point closely adjacent its bottomy with an aperture to receive a cork or packing element l5 which element, which ispreferably fabricated of rubber, is axially perforated to receive the horizontally extending tube Aor duct I5 the inner end of which, indicated at I6', is upwardly directed as shown and terminates in discharge port or nozzle. It is through the duct I6 that the rinsing liquid is introduced into the container I2 and the rate of iniiow of such liquid may be regulated, as by meansy of theV control valve. diagrammatically in- Y ture formed in the side of the container.

dicated at I1. A syphon is generally indicated at S, this syphon having a portion of one leg within the container and the other leg wholly without the container, the upper ends of the two legs being connected by the curved portion 20. 'Ihus the outer leg 2l of the syphon extends from the curved portion 23 to a point below the bottom of the container I2.

The inner leg is formed in three sections, a relatively short section 22 which is integral with the curved portion 2l), an intermediate section 23, and a lower section 24. 'Ihe lower section has its lower end terminating just above the bottom of container I2 and is provided with a horizontally disposed integral part 24 adjacent its upper end which passes through a central aperture formed in a cylindrical bushing or packing member 25 fabricated of rubber or the like and which tightly engages the cylindrical wall surface of an aper- Part 24 is also. integral with the upper terminalv portion 2l2 of the lower leg section, which terminal portionv is parallel to the outer leg 2|. The intermediate section 23 is detachably connected to the upper and lower sections. 22 andY 24 by cou-l pling members or. sleeves 26' and'2'l, respectively, and by this arrangement vertical adjustment of the position of the curved upper portion 2 of the syphon may be readily effected'. Thus, if it be desired that the curved portion 25 be lowered, section 2;? of the inner'leg of the syphon may be removed and replaced by a shorter section.

The diameter of the tube of which the syphon is formed is substantially greater than the diameter of the tube I6 through which rinsing liquid is introduced into the container and the syphon will, when it becomes active, and with the rate ofA fluid inowY relativelyV low, as is preferred, evacuate a body of liquid which may be within the container in much less time than was required to introduce the. liquid. In the ordinary use of the rinsing mechanism water will be caused to flow into the bottom of the container in a constant stream and the level of the surface of this liquid'will gradually rise, both within and without the holder I0, the water flowing intorthe interior of: the holder through the apertures I2 in the bottom, and into the space between the concentric holder and container walls through the apertures 3G. and 3| formed as notches or cutouts in the lower margin of the holder bottom Ill.

The rinsing Huid passing into the holder will, in part, pass upwardly between the several pipettes or other tubes which the holder contains and in part will pass upwardly through the elongated apertures formed in these tubular elements, each pipette or tube being washed or rinsed both lnterorly and exteriorly. 'Ihe inflow of rinsing liquid. will continue uninterruptedly until the pipettes or tubes within the holder are completely" immersed, for instance rising to thelevel indicated by the line A-A in Figure 2; When the liquidlevel rises to this point, however, the inner legof the syphon is completely full and liquid begins to ow over into the outer leg 2| of the syphon, thus starting the syphon action, the syphon action continuing relatively rapid-ly until the container I2 is substantially emptied of its washing liquid.

When the lower end of the inner leg of the syphon is exposed, the syphon is` broken and the outflowy of wash liquid is discontinued, the iniiow continuing, however, until the level of the surface ofthe liquid within the container I2- again gradually` rises until it reaches the level indicated by the line A-A. At this point the syphon action is again commenced and the container is again emptied. If desired, the lower portion 24 of the inner leg of the syphon may be provided, near the bottom thereof, with an aperture 32 to effect interruption of the syphon action at a point above the bottom to the tube, when the inflow of water through the tube or duct I6 is relatively rapid.

It will be observed that the two notches or cutouts 3| are relatively large and it is essential that such apertures be formed in the periphery of the bottom member I0 to receive the tubular section 24 of the syphon as the holder is introduced into and withdrawn from the container I2, the diametrically opposed notch or recess 3| receiving the water duct or conduit I6 when the holder is resting on the container bottom. The rinsing ac- EJK tion may be allowed to continue indefinitely but,

of course, to avoid wastage of water, the action is stopped after the pipettes have been thoroughly rinsed.

It will be seen that the apparatus comprises three essential major portions; the holder, which functions as a receptacle for pipettes; the container for the chromic or other cleaning fluid and the container for the rinsing fluid, with its associated means for effecting withdrawal of water which has been once used for rinsing and the prompt if not immediate replacement of the water removed with a fresh body of rinsing water. The several elements of the invention are of the utmost simplicity, are attractive in appearance, and quite inexpensive to fabricate and use. Obviously, minor changes may be made without departure from the invention.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for cleansing with liquid elongated tubular open ended elements, comprising, in combination, a cylindrical vertically disposed container having an inlet conduit for cleaning liquid, said conduit entering through the side wall of the container adjacent to the bottom and extending inwardly along said bottom surface and opening at a centrally disposed point, an automatio. intermittently actuated siphon outlet means for the container, a removable holder for introducing said elements into the container, said holder being substantially cylindrical and provided with a substantially conical upwardly bulged perforated bottom wall, said bottom wall extending downwardly to form flared lower marginal edges, said flared edges being notched to accommodate said inlet conduit.

2. Apparatus for cleansing with liquid elongated tubular open ended elements, comprising, in combination,a cylindrical vertically disposed container, an inlet conduit for cleaning liquid opening into said container, an inverted U-shaped tube providing an automatic intermittently actuated outlet Siphon for the container, at least a portion of one leg of said tube being disposed interiorly of said container and close to the wall thereof, a removable holder for introducing said elements into the container, said holder being substantially cylindrical and provided with a perforated bottom wall and flared lower marginal edges, the walls of the holder being spaced from the walls of the container and the flared bottom edges of said holder being approximately the same diameter as the internal diameter of said container with suicient clearance for ready removal, said flared edges being notched to provide for the passage thereof past the inner leg of the U-shaped siphon tube.

ETI-IAN ALLAN BROWN. NORBERT BENOT'II. 

